Electronic devices can make use of memory for storage in relation to operations performed by a central processor. A number of different types of memory formats are available to computers. ROM (Read-Only Memory) is a common form of electronic device memory that is a non-volatile memory type written to one time. Non-volatile memory is a storage type that retains data without constantly drawing power (e.g., without being connected to an electrical outlet and being in an ‘on’ state). ROM systems can read stored data, but ROM systems do not re-write new information upon previously used memory blocks.
Another type of memory typically employed by an electronic device is RAM (Random Access Memory). RAM is a storage type that enables data to be read in a storage sequence independent of order. RAM is commonly the main working area for an electronic device; however, other configurations are possible that use other memory types for a main working area. An electronic device can read the information stored in the RAM as well as write new information to the RAM. However, a problematic feature with RAM is that many types of RAM are volatile memory types (e.g., need to draw from a constant source of power to retain memory).
A common form of RAM is Dynamic Random Access Memory (DRAM); however, other RAM types are available (e.g., Static Random Access Memory). In an integrated circuit, bits of data are saved in individual capacitors. The capacitors lose voltage due to natural leakage and stored data is lost unless there is recharging of the capacitor. The reason for the term Dynamic is that the term refers to a continuous action taking place (e.g., the steady recharging of the capacitor/loss of voltage). There are several variations on DRAM, such as video DRAM